ispose the
system to disease. The change from inhaling a fluid poison at blood
heat, to inhaling the purer air without at the freezing point or below,
is greater than the system can bear with impunity.

A uniform temperature, which is highly important, can be more easily and
more effectually maintained where a stove is employed, furnished with a
damper, and supplied with dry, hard wood, than where a fire-place is
used. In the former case the draft may be regulated, in the latter it
can not be. A great amount of air enters into combustion even where a
stove is used. A greater quantity enters into the combustion where a
fire-place is used, in proportion to the increased amount of wood
consumed. Much of the heated air, also, where an open fire-place is
used, mingling with the smoke, passes off through the chimney, and its
place is supplied by an ingress of cold air at the more distant portions
of the room. There is hence not only a great waste of fuel, but a
sacrifice of comfort, health, and life.

But even where a stove is used there is a constant ingress of cold air
through cracks and defects in the floor, doors, windows, and walls,
which causes it to be colder in the outer portions of the room than in
the central portions and about the stove. The evil is the same in kind
as that already referred to in speaking of fire-places, but less in
degree. This evil, however, may be almost entirely obviated by a very
simple arrangement, which will also do much to render ventilation at
once more effectual and safe, especially in very cold and inclement
weather. The arrangement is as follows:

Immediately beneath the floor--and in case the school-house is two
stories high, between the ceiling and the floor above--insert a tube
from four to six inches in diameter, according to the size of the rooms,
the outer end communicating with the external air by means of an orifice
in the under-pinning or wall of the house, and the other, by means of an
angle, passing upward through the floor beneath the stove. This part of
the tube should be furnished with a register, so as to admit much or
little air, as may be desirable. This simple arrangement will reverse
the ordinary currents of air in a school-room. The cold air, instead of
entering at the crevices in the outer part of the room, where it is
coldest, enters directly beneath the stove, where it is warmest. It thus
moderates the heat immediately about the stove, and being warmed as it
en